Your 90-year-old self would give anything to be where you are right now. Lift weights, walk, eat healthy, and sleep well. You are living your golden years right now. You're younger than you think you are. Don't waste it.
If you ever feel like giving up, then take a break. Not everyone gets it right on the first try. Sometimes, you need to step away, go home, gather your thoughts, and figure out what went wrong and what you can do better.
Quit forcing it for the moment if you have to.. but don’t quit on yourself. Reset, learn the lesson, and come back stronger. The story isn’t over yet, brother.